HD404449 Datasheet, PDF (79/123 Pages) Hitachi Semiconductor – HD404449 SERIES

HD404449 Series
Serial Interface
The MCU has two channels of serial interface. The transfer and receive start instructions differ according
to the serial interface channel, but other functions are the same. The serial interface serially transfers or
receives 8-bit data, and includes the following features.
• Multiple transmit clock sources
 External clock
 Internal prescaler output clock
 System clock
• Output level control in idle states
Five registers, an octal counter, and a multiplexer are also configured for serial interfaces 1 and 2 as
follows.
Serial interface 1
• Serial data register 1 (SR1L: $006, SR1U: $007)
• Serial mode register 1A (SM1A: $005)
• Serial mode register 1B (SM1B: $028)
• Port mode register A (PMRA: $004)
• Miscellaneous register (MIS: $00C)
• Octal counter (OC)
• Selector
Serial interface 2
• Serial data register 2 (SR2L: $01D, SR2U: $01E)
• Serial mode register 2A (SM2A: $01B)
• Serial mode register 2B (SM2B: $01C)
• Port mode register A (PMRA: $004)
• Octal counter (OC)
• Selector
The block diagram of serial interfaces 1 and 2 are shown in figure 66.
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